Hey there, let's break down what's likely going on here—your GTX 1080, 32GB RAM, and i7-8700K are way more than enough to run Unity 2018 smoothly, so this is almost certainly a post-update quirk rather than a hardware limitation. Here are the most common fixes to try, ordered by how likely they are to resolve the issue:

• Clear Unity's cached project data
  Unity stores a massive amount of cached assets and metadata in the Library folder, which often gets corrupted or incompatible after a version jump. Close Unity entirely, delete the Library folder in your project directory, then reopen Unity. This will force it to rebuild all cached assets from scratch—yes, it takes a few minutes, but it fixes 90% of post-update performance issues. Also, if you use baked global illumination, delete the LightingData.asset file (usually in Assets/StreamingAssets or your lighting settings folder) and rebake your lighting; old baked data from a previous Unity version can tank frame rates.

• Adjust GPU driver versions
  Unity 2018.1 has specific driver compatibility needs. Sometimes newer Game Ready drivers introduce bugs with older Unity builds, or outdated drivers miss optimizations for 2018.x. Try updating to the latest driver for your GTX 1080, and if that doesn't help, roll back to a driver released around mid-2018 (when Unity 2018.1 launched)—those are often perfectly tuned for this specific Unity version.

• Audit third-party plugins and custom assets
  Outdated plugins are the #1 culprit for post-update lag. Go through your Assets/Plugins folder and check if any tools (like input managers, shader packs, or editor extensions) have updates for Unity 2018.x. Also, inspect custom shaders—some older shaders aren't optimized for DX11 in 2018, or have bugs that cause GPU overload. Try temporarily disabling non-essential plugins/shaders to see if performance bounces back.

• Tweak Unity editor performance settings
  Open Edit > Preferences > Performance and disable VSync—it can cap your frame rate unexpectedly even on high-end hardware. In the Game view, toggle off Gizmos and Stats (they add unnecessary overhead). Also, go to Edit > Project Settings > Player > Other Settings and set Graphics API to Automatic instead of forcing OpenGL; forcing an API that's not optimized for your project/hardware often makes things worse.

• Use the Profiler to pinpoint bottlenecks
  Open the Unity Profiler (Window > Analysis > Profiler) and check the CPU and GPU tabs for consistent high usage. Look for infinite loops in scripts, textures loading at way higher resolutions than intended, or unexpected asset loads. The Memory tab can also reveal if post-update, Unity is holding onto way more assets than it should.

• Test with a fresh project
  If all else fails, create a new empty Unity 2018.1.0f2 project and add basic objects (cube, light, camera). If it runs smoothly, the issue is specific to your existing project—migrate assets to the new project incrementally to find which one is causing the lag. If the fresh project is also slow, reinstall Unity 2018.1.0f2; the initial update might have corrupted some installation files.

内容的提问来源于stack exchange，提问作者kognise